1. Field of the Invention
The present invention relates to a differential pressure sensor which is computer compensated for reference pressure effects.
2. Prior Art
High accuracy is required for differential pressure measurements in the aerospace industry. The need for high accuracy differential pressure measurement in aerospace applications has forced the measurement of two absolute pressures using two absolute pressure sensors and then computing the difference in pressure. This type of measurement, even when pressure nonlinearity and temperature dependent errors were digitally corrected resulted in relatively large errors as a percent of required differential pressure measurements because the difference in pressure is small compared to the absolute pressures measured.
Differential pressure sensors whose differential pressure nonlinearity and temperature dependent errors were adjusted by analog circuitry and whose reference pressure dependence was mechanically compensated also failed to meet the required accuracy for differential pressure measurements. Differential pressure sensors using already available reference pressure signals for compensation by noninterchangeable analog circuitry have also failed to meet such standards.